In open cut or underground mining operations, a drilling and blasting engineer typically designs a drill pattern for a blasting site based on parameters such as rock burden including rock type and density, spacings between blastholes, borehole depth and diameter for a predetermined explosive material, and where required, blasthole orientation and angles.
In some instances the drill pattern is then surveyed and pegged out by the drilling team. Each blasthole peg is tagged and provided with a unique blasthole number. The driller drills the blastholes in accordance with the drill pattern and manually records each blasthole number and respective blast hole depth. Alternatively, the drill pattern is transferred electronically to a drill rig which then uses a global positioning system (GPS) to locate and identify positions of each blast hole.
Prior to commencement of loading of the blastholes with explosives, all blast holes are typically reinspected with respect to conformance to drill pattern including the consistency of hole sizing and depth and orientation of the blast holes. If any blast holes are found to be too shallow, too deep, out of position or there is a requirement for extra holes due to excessive burden, then this information is conveyed back to the drilling and blast engineer to authorise corrective action as soon as practicable.
After drilling, samples from each blast hole are taken for mineral testing, each sample being tagged with the corresponding unique blast hole number. The blast hole number is then retrieved from each bag and loaded into a data tracking system.
The blast crew then manually records the blast hole loading data comprising date, time, shot firer, pattern number, blast hole number, individual blast hole depth, quantities and relative bulk strength of explosive material loaded into each blast hole, delay number, number of detonators or primers loaded into the blast hole, stemming height, and returns the blast hole loading data to the drilling and blasting engineer.
Typically, a correlation of blast holes against explosive materials is then made by checking that the number of holes loaded with explosives corresponds to the number of holes drilled. This information is then cross-referenced against magazine stock records to check if all explosive materials is accounted for, and the data is then cross-referenced against the drill pattern. As the two sets of information recorded by the driller and the blast crew are manually recorded, it is a time consuming process to transfer this data to a computer in order to complete the resolution process, and subject to human error.
The present invention seeks to overcome at least some of the aforementioned disadvantages.